THYMUS - Teratoma, malignant

A lobulated tumour, approximately half of it cystic and containing gelatinous material. Towards one side there is a circumscribed nodule some 8 x 5 cm.; the surface shows a number of blood vessels, much solid tissue and a number of cystic spaces. The white material in the cystic area is not explained.
This young man was referred for investigation at the age of 19 because a miniature X-ray had shown an abnormal mediastinal shadow. Various investigations were done, including angiography, which established the presence of an anterior mediastinal mass, which was subsequently removed. An enlarged lymph node was found in the left tracheobronchial angle, and tumour tissue was present at the apex of the left upper lobe of the lungs. Microscopy established that this was a well-differentiated terratoma, with the usual benign, well-organised elements but with, in addition, malignant tissue classified as "endodermal sinus tumour (yolk-sac carcinoma)". He died from his disease within 2 months.